Serum Protein Electrophoresis

Sample for Serum Protein Electrophoresis

1. This is done on the serum of the patient.
2. Also can be done in the urine. 24 hours of urine is preferred.
3. CSF for the oligoclonal band.

Indications for Serum Protein Electrophoresis

1. This can diagnose some inflammatory diseases.
2. It can diagnose neoplastic diseases like multiple myeloma and lymphoma.
3. Advised In immune disorders.
4. Advised In liver diseases.
5. Advised In nephrotic syndrome.
6. Advised In Chronic edema.
7. To detect monoclonal proteins (Immunoglobulins).
8. CSF for the oligoclonal band.

Definition of electrophoresis: 

1. This is the migration of charged solutes or particles in a liquid medium under the influence of the electrical field.
2. Analytes of interest are:
   1. Proteins.
   2. Peptides.
   3. Aminoacids.
   4. Nucleic acid.
   5. OLigonucleotides.
   6. Cations in body fluids and the tissue.

Pathophysiology of serum proteins:

1. Proteins are constituents of muscles, hormones, hemoglobin, and transport protein,
   1. Serum proteins are a source of nutrition and a buffer system.
   2. Immunoglobulins have a function in the immune system.
2. Carrier proteins, like haptoglobins, prealbumin, and transferrin, transport certain ions and molecules to their site of action.
3. Some of the protein regulates:
   1. The activity of various proteolytic enzymes.
   2. The osmotic pressure within the vascular compartment.
   3. Metabolic substances like a hormone.
4. Immunoglobulins are a major component of gamma-globulins.
   1. In a normal person, the immunoglobulins are of polyclonal nature.
   2. The monoclonal band of immunoglobulin indicates a neoplastic process like multiple myeloma and Waldenstrom’s macroglobulinemia.
5. Serum electrophoresis separates proteins into 5 different bands:
   1. Albumin, and Prealbumin. Albumin is formed in the liver and is 60% of total proteins.
   2. alpha1-globulin (α₁-globulin).
   3. alpha 2-globulin (α₂-globulin).
   4. beta – globulin (β-globulin).
   5. gamma – globulin (γ-globulin).

The pattern of different bands 0n Serum Protein Electrophoresis:

1. These different bands have different zone with the characteristic presence of different proteins. e.g.
   1. The Albumin zone shows only albumin.
   2. alpha1- zone shows :
      1. alpha1 – lipoprotein.
      2. High-density lipoprotein (HDL)
      3. Alpha-1 -antitrypsin.
   3. Alpha 2 zone shows:
      1. Alpha-2 macroglobulins.
      2. Haptoglobin.
      3. β -lipoprotein.
   4. Beta zone shows:
      1. Transferrin.
      2. Complement 3 (C3).
   5. Gamma zone shows
      1. Fibrinogen.
      2. IgA.
      3. IgM.
      4. IgG.

Functions of proteins:

Albumin :

1. Maintain the colloidal osmotic pressure.
2. Albumin also transports drugs, hormones, and enzymes.
3. Albumin measures liver function. In liver diseases, its concentration will be markedly low when there is liver cell damage.
4. The half-life of Albumin is 12 to 18 days, so that liver cell damage will be shown after this period.

Globulins :

1. These are the main component of immunoglobulins (Antibodies).
2. Some are transporting proteins like thyroid and cortisol binding proteins.
3. Haptoglobin binds hemoglobin during hemolysis.
4. Ceruloplasmin is a carrier of copper.
5. They may also act as transport vehicles.

Principle of Electrophoresis

1. This is basically the separation or migration of charged solutes of particles in a liquid medium under the influence of the electrical field.
2. Chemical substances carrying charges because of ionization moves towards either cathode ( Negative electrode ) or anode ( positive electrode ). So the protein ions ( cation ) move toward the cathode, and negative ions ( anion ) move toward the anode.
3. Serum Electrophoresis can separate the various components of blood proteins into bands or zones according to their electrical charge under the influence of electrical current.
   1. Zones of proteins are separated from the neighboring zones.
   2. Then these zones are visualized by the stains.
   3. The support medium is dried and can quantify each zone by the densitometer.
   4. The support medium can be kept permanently after drying.
4. The rate of migration depends upon the following:
   1. The net electrical charge of the molecule.
   2. Size and shape of the molecule.
   3. Electrical field strength.
   4. The temperature of the medium.
   5. Properties of the support medium.
5. Urine electrophoresis classifies renal protein-losing nephropathies.
6. CSF electrophoresis diagnoses the monoclonal band.

The components needed for electrophoresis are:

1. Tank with power supply (electrical field).
2. Electrode, either carbon or platinum.
3. Buffer system (in the buffer tanks).
4. support media like :
   1. agar gel.
   2. agarose.
   3. Cellulose acetate.
   4. Polyacrylamide.
5. Stains. This is used to visualize the separate bands.
6. Densitometer to read the different bands and quantitate them.
7. The automated system automatically electrophoresis instead of a manual method.

Normal Serum Protein Electrophoresis

Source 1

Total Proteins in Adult

• To convert into SI unit x 10 = g/L

Source 2

• Total protein = 6.4 to 8.3 g/dL.
• Albumin = 3.5 to 5 g/dL.
• Globulin = 2.3 to 3.4 g/dL.
  • alpha 1 globulin = 0.1 to .3 g/mL.
  • alpha 2 globulin = 0.6 to 1.0 g/dL.
  • beta globulin = 0.7 to 1.1 g/dL.

Children

• Total protein :
  • Premature infants = 4.2 to 7.6 g/dL.
  • Newborn = 4.6 to 7.4 g/dL.
  • Infants = 6.0 to 6.7 g/dL.
  • Child = 6.2 to 8.0 g/dL.
• Albumin :
  • Premature infants = 3.0 to 4.2 g/dL.
  • Newborn = 3.5 to 5.4 g/dL.
  • Infants = 4.4 to 5.4 g/dL.
  • Child = 4.0 to 5.9 g/dL.

Source 1

Protein electrophoresis on cellulose acetate:

Serum Protein Electrophoresis on Agarose:

Increased Total Protein (Hyperproteinemia) seen in:

1. Dehydration and hemoconcentration due to fluid loss like vomiting, diarrhea, and poor kidney function.
2. Liver diseases.
3. Multiple myelomas.
4. Gammopathies.
5. Waldenstrom’s globulinemia.
6. Sarcoidosis and other granulomatous diseases.
7. Autoimmune diseases like SLE and Rheumatoid arthritis.
8. Chronic inflammation.

Decreased Total protein (Hypoproteinemia) seen in:

1. Severe liver disease.
2. Renal disease, nephrotic syndrome.
3. Starvation and malabsorption.
4. Diarrhea, ulcerative colitis, and Crohn’s disease.
5. Severe burn.
6. Skin diseases.
7. Hypothyroidism.
8. Heart failure.

Increased Albumin is seen in:

1. Dehydration.
2. Intravenous infusion.

Decreased Albumin is seen in:

1. Liver diseases.
2. Alcoholism.
3. Malabsorption.
4. Nephrotic syndrome.
5. Starvation.
6. Protein-losing enteropathies like Crohn’s disease and Whipple’s disease.
7. Ascites.
8. Congenital albuminemia.
9. Pregnancy.
10. Overhydration.
11. Autoimmune diseases like systemic lupus erythematosus.

Increased α-1 globulin seen in:

1. Biliary Cirrhosis.
2. Obstructive jaundice.
3. Multiple myelomas.
4. Kidney disease like nephrosis.
5. Acute and chronic infection.
6. Ulcerative colitis.

Decreased α-1 globulin seen in:

1. Kidney diseases like nephrosis.
2. Acute Hemolytic anemia.
3. Juvenile pulmonary emphysema.

Increased α-2 globulin seen in:

1. Kidney disease like nephrotic syndrome.
2. The inflammatory disease is due to an increase in the acute phase proteins.

Decreased α-2 globulin seen in:

1. In hemolysis because haptoglobin is alpha-2-globulin which will decrease in hemolysis.
2. Wilson’s disease.
3. Hyperthyroidism.
4. Liver disease occurs when liver function is defective.

Increased β- globulin is seen in:

1. Biliary Cirrhosis.
2. Obstructive jaundice.
3. Neoplasm-like multiple myeloma.
4. In all, hypercholesterolemia may be due to hypothyroidism and nephrosis.
5. Iron-deficiency anemia.

Decreased β- globulin is seen in:

1. Kidney diseases like nephrosis.
2. Malnutrition.

Increased  γ- globulin is seen in:

1. Hepatic diseases like cirrhosis.
2. Acute and chronic infections.
3. Multiple myelomas.
4. Autoimmune diseases like SLE and rheumatoid arthritis.
5. Waldenstrom’s macroglobulinemia.
6. Leukemia.
7. Malignancies like Hodgkin’s lymphoma and lymphomas.

Decreased γ- globulin is seen in:

1. Nephrotic syndrome.
2. Agammaglobulinemia.
3. hypogammaglobulinemia.
4. An immune deficiency may be due to infections, steroid therapy, or lymphomas.

Monoclonal Gammopathy:

• It is seen in some malignant processes like multiple myeloma.

• Please see more details on Protein Total.